Comparison of immune modulatory properties of human multipotent mesenchymal stromal cells derived from bone marrow and placenta

Multipotent mesenchymal stromal cells (MSC) can be isolated from many tissues, including bone marrow (BM) and placenta (PL). Human placenta can be obtained readily without invasive procedures. There may be differences, however, in differentiation capacity and immunomodulation by MSC isolated from BM or PL. The early pregnancy factor (heat shock protein 10; EPF/Hsp10) is a small protein that exhibits immunomodulatory properties. We compared BM- and PL-MSC, and assessed their efficacy for suppressing T-cell proliferation in vitro and the role of EPF/Hsp10 in this process. PL-MSC were collected from whole placenta after removal of the amniotic and chorionic membranes followed by serial enzymatic digestions. The PL-MSC were compared to BM-MSC, obtained from healthy donors. Differentiation capacity, cytokine secretion, expression and secretion of immunomodulatory molecules, immunophenotype and real time proliferation were assessed using cytokine arrays, ELISA assays, flow cytometry, immunohistochemical staining and western blotting. Whereas BM-MSC consisted of a homogeneous cell population with strong expression of mesenchymal markers, PL-MSC consisted of a mixed population of cells with variable CD73, CD90 and CD105 expression. PL-MSC exhibited a significantly greater proliferation rate than BM-MSC. The presence of both stem cells and more mature cells in the PL-MSC cultures resulted in decreased differentiation capacity and reduced efficacy of immune suppression in co-cultures with T-cells. Although robust intracellular expression of EPF/Hsp10 in both BM- and PL-MSC was observed, secretion of the protein in response to immune activating stimuli remained below detectable levels. Secretion of pro-inflammatory cytokines was significantly greater in BM-MSC than PL-MSC, whereas no difference was observed in the secretion of hematopoiesis supporting growth factors. Development of culture methods for isolation of pure populations of PL-MSC may improve the quality of the product and reproducibility of results.

Structural order and charge transfer in highly strained carbon nanobelts

We present a computational study of the atomic morphology, structural order and charge transfer properties of radially π-conjugated, closed-loop, and highly strained chiral carbon nanobelts (CNBs).

Rapid emergence of colistin resistance and its impact on fatality among healthcare-associated infections

This article describes the emergence of resistance and predictors of fatality for 1556 cases of healthcare-associated Gram-negative bloodstream infection in 2014 and 2015. The colistin resistance rate in Klebsiella pneumoniae was 16.1%, compared with 6% in 2013. In total, 660 (42.4%) cases were fatal. The highest fatality rate was among patients with Acinetobacter baumannii bacteraemia (58%), followed by Pseudomonas aeruginosa (45%), Klebsiella pneumoniae (41%), Enterobacter cloacae (32%) and Escherichia coli (28%). On multi-variate analysis, the minimum inhibitory concentrations for carbapenems [odds ratio (OR) 1.02, 95% confidence interval (CI) 1.01-1.04; P = 0.002] and colistin (OR 1.1, 95% CI 1.03-1.17; P = 0.001) were found to be significantly associated with fatality.